halfmesh_concepts.h

// Description: Concepts for the half-edge structure

#ifndef PASTELGEOMETRY_HALFMESH_CONCEPTS_H
#define PASTELGEOMETRY_HALFMESH_CONCEPTS_H

#include "pastel/geometry/halfmesh/halfmesh_fwd.h"

namespace Pastel
{

    namespace HalfMesh_Concepts
    {

        //! Half-edge structure settings
        class Settings
        {
        public:
            // Define a data type as void to avoid 
            // allocating any memory for that data.

            //! The user-data stored at the vertices.
            using VertexData = UserDefinedType;

            //! The user-data stored at the half-edges.
            using HalfData = UserDefinedType;

            //! The user-data stored at the edges.
            using EdgeData = UserDefinedType;

            //! The user-data stored at the polygons.
            using PolygonData = UserDefinedType;

            //! Whether to allow multiple edges between two vertices.
            static constexpr bool MultipleEdges = UserDefinedBoolean;

            //! Whether to allow equal end-vertices for an edge.
            static constexpr bool Loops = UserDefinedBoolean;
        };

        //! Half-edge structure customization
        template <typename Settings>
        class Customization
        {
        public:
            // Since the HalfMesh inherits from its customization,
            // you can extend the public interface of the HalfMesh
            // by specifying public functions.

        protected:
            // The customization functions should be protected
            // so that they can only be called by the HalfMesh
            // implementation.

            using Fwd = HalfMesh_Fwd<Settings>;
            PASTEL_FWD(Vertex_Iterator);
            PASTEL_FWD(Half_Iterator);
            PASTEL_FWD(Edge_Iterator);
            PASTEL_FWD(Polygon_Iterator);

            //! Constructs an empty customization.
            /*!
           Exception safety: basic
           */
            Customization() {}

            //! Swaps two customizations.
            /*!
           Time complexity: O(1)
           Exception safefy: nothrow
           */
            void swap(Customization& that) {}

            //! Called at the start of clear().
            void onClear() {}

            //! Called at the end of insertVertex().
            void onInsertVertex(const Vertex_Iterator& vertex) {}

            //! Called at the start of removeVertex().
            void onRemoveVertex(const Vertex_Iterator& vertex) {}

            //! Called at the end of insertEdge().
            void onInsertEdge(const Edge_Iterator& edge) {}

            //! Called at the start of removeEdge().
            void onRemoveEdge(const Edge_Iterator& edge) {}

            //! Called at the end of insertPolygon().
            void onInsertPolygon(const Polygon_Iterator& polygon) {}

            //! Called at the start of removePolygon().
            void onRemovePolygon(const Polygon_Iterator& polygon) {}

        private:
            // These functions will not be used, and so should
            // be deleted to avoid accidental splicing.
            Customization(const Customization& that) = delete;
            Customization(Customization&& that) = delete;
            Customization& operator=(Customization) = delete;

            // You can introduce customization state here.
        };

    }

}

#endif